When we think of electronic communications it is natural to think first of television because we see it so frequently. While television is an extremely important part of the communication area, we should not limit our thinking to it alone. If we take electronic communications to mean the conveying of information from point-to-point by means of electromagnetic waves, then we must consider many applications other than television. Radiotelephony and radiotelegraphy are perhaps the most obvious of these other applications. Less obvious, but nevertheless extremely important, are the various types of radar, telemetry, and remote control applications.
Each of these many application areas is a technical specialty within itself. We could never hope to cover all of them in detail within a single volume. There are, however, a number of basic communication principles which are shared by all of these application areas. In this volume we shall cover a number of these basic areas including: receivers, transmitters, and introductory communications systems. Try to keep in mind that while a principle may be illustrated by a specific application, the principle applies to many other applications as well.
- RADIO RECEIVERS 1
- MODULATION AMPLIFIERS 13
- AM DETECTORS 20
- IF AMPLIFIERS 27
- AUTOMATIC GAIN CONTROL 32
- OSCILLATORS 42
- HETERODYNING 50
- RECEIVER TROUBLESHOOTING 60
- RF AMPLIFIERS 69
- AMPLITUDE MODULATION 81
- PULSE TELEMETRY SYSTEMS 94
- DIGITAL ENCODER CIRCUITRY 108
- CERAMIC IF FILTERS 120
- DECODER CIRCUITRY 129
- DIGITAL SERVO 140
This manual, along with the others in the Electromechanical Technology Series, is the result of six years of research and development by TERC, a national nonprofit, public service corporation with headquarters in Cambridge, Massachusetts. It has undergone a number of revisions as a direct result of experience gained with students in technical schools and community colleges throughout the country.